The development and testing of a smart sensorized guide wire for catheterization in a "blood" vessel phantom to support aortic valve implementation.

PURPOSE: Heart valve disease is commonly treated by minimally invasive procedures with guide wires and catheterization. The main purpose of this study is to find out whether an extension of the guide wire with a sensor can support the surgeon within the blood vessel to reduce X-ray necessity. METHODS: A smart guide wire is developed by an extension with a flex-bending sensor to evaluate the sensor signal with and without "blood" flow at a constant compression force. Various surgically relevant investigations are performed. For assessment, the mean temporal average of the moving averaged filtered ADC signal and a subsequent FFT are carried out. RESULTS: Results show that there is a smaller sensor signal when the applied force or bending at the sensor is higher. In all investigations, there was a different sensor signal. The flex-bending sensor can detect the effect of pulsatile flow. The smallest temporal averaged signal difference between reference and clamp in the front wire's tip is 1.09%. For example, the mean temporal average of the filtered ADC signal for different clinically relevant scenarios is between 2550 and 2900. CONCLUSIONS: The results show that the sensorized guide wire developed for catheterization can support aortic valve implementation. The sensor sensitivity is sufficient to detect even very small variations within the blood vessel and therefore is promising to support catheterization heart valve surgeries in future.

Impact of myocardial injury after coronary artery bypass grafting on long-term prognosis.

AIMS: The most appropriate definition of perioperative myocardial infarction (pMI) after coronary artery bypass grafting (CABG) and its impact on clinically relevant long-term events is controversial. We aimed to (i) analyse the incidence of pMI depending on various current definitions in a 'real-life' setting of CABG surgery and (ii) determine the long-term prognosis of patients with pMI depending on current definitions. METHODS AND RESULTS: A consecutive cohort of 2829 coronary artery disease patients undergoing CABG from two tertiary university centres with the presence of serial perioperative cardiac biomarker measurements (cardiac troponin and creatine kinase-myocardial band) were retrospectively analysed. The incidence and prognostic impact of pMI were assessed according to (i) the 4th Universal Definition of Myocardial Infarction (4UD), (ii) the definition of the Society for Cardiovascular Angiography and Interventions (SCAI), and (iii) the Academic Research Consortium (ARC). The primary endpoint of this study was a composite of myocardial infarction, all-cause death, and repeat revascularization; secondary endpoints were mortality at 30 days and during 5-year follow-up. There was a significant difference in the occurrence of pMI (49.5% SCAI vs. 2.9% 4UD vs. 2.6% ARC). The 4th Universal Definition of Myocardial Infarction and ARC criteria remained strong independent predictors of all-cause mortality at 30 days [4UD: odds ratio (OR) 12.18; 95% confidence interval (CI) 5.00-29.67; P < 0.001; ARC: OR 13.16; 95% CI 5.41-32.00; P < 0.001] and 5 years [4UD: hazard ratio (HR) 2.13; 95% CI 1.19-3.81; P = 0.011; ARC: HR 2.23; 95% CI 1.21-4.09; P = 0.010]. Moreover, the occurrence of new perioperative electrocardiographic changes was prognostic of both primary and secondary endpoints. CONCLUSION: Incidence and prognosis of pMI differ markedly depending on the underlying definition of myocardial infarction for patients undergoing CABG. Isolated biomarker release-based definitions (such as troponin) were not associated with pMI relevant to prognosis. Additional signs of ischaemia detected by new electrocardiographic abnormalities, regional wall motion abnormalities, or coronary angiography should result in rapid action in everyday clinical practice.

[Incidental finding of a cardiac paraganglioma]. / Zufallsbefund eines kardialen Paraganglioms.

Cardiac paragangliomas are extremely rare neoplasms with an incidence of 1% of all cardiac tumors and can be completely asymptomatic, therefore, diagnosis is difficult. This article reports the case of an 18-year-old man with a heart murmur detected during a routine physical examination. Echocardiography revealed a heart tumor measuring 7 cm in size in the right atrium. Due to the tumor size and the threat of tricuspid valve insufficiency, tumor resection was performed. The histopathological examination revealed a cardiac paraganglioma with positive reactions of the tumor cells for chromogranin A, synaptophysin and CD56. Differentiating a primary cardiac paraganglioma from other more common cardiac tumors and particularly from metastases of neuroendocrine neoplasms from other locations is essential not only for the further clinical treatment but also for the prognosis of the patient.

Coil embolization of internal mammary artery injured during central vein catheter and cardiac pacemaker lead insertion.

PURPOSE: This study describes several cases of endovascular coil embolization of the proximal internal mammary artery injured by blind approach to the subclavian vein for central venous catheter or pacemaker lead insertion. MATERIALS AND METHODS: We conducted a retrospective analysis of five patients with iatrogenic arterial lesions of the internal mammary artery (IMA). The lesions occurred in three patients from a puncture of the subclavian vein during insertion of a central venous catheter and in two patients from a puncture of the subclavian vein for insertion of a pacemaker lead. Four patients had acute symptoms of bleeding with mediastinal hematoma and hematothorax and one patient was investigated in a chronic stage. A pseudoaneurysm was detected in all five patients. All four acute and hemodynamic unstable patients required hemodynamic support. RESULTS: In all patients, embolization was performed using a coaxial catheter technique, and a long segment of the IMA adjacent distally and proximally to the source of bleeding was occluded with pushable microcoils. In one patient, additional mechanically detachable microcoils were used at the very proximal part of the IMA. Microcoil embolization of the IMA was successful in all patients, and the source of bleeding was eliminated in all patients. CONCLUSION: Transarterial coil embolization is a feasible and efficient method in treating acute bleeding and pseudoaneurysm of the IMA and should be considered if mediastinal hematoma or hemathorax occurs after blind puncture of the subclavian vein.

CCR3- and CXCR4-mediated interactions regulate migration of CD34+ human bone marrow progenitors to ischemic myocardium and subsequent tissue repair.

OBJECTIVE: Hematopoietic progenitor cells are able to induce neovascularization of ischemic myocardium, inhibit apoptosis, and prevent heart failure. They express functional CC chemokine-binding receptor 3 (CCR3) and CXC chemokine-binding receptor 4 (CXCR4); however, the role of those receptors in migration of progenitor cells into the ischemic myocardium is unknown. METHODS: Myocardial infarction was surgically induced in athymic nude rats, and human bone marrow-derived CD34+ cells or saline was injected into the tail vein. Cell chemotaxis was studied in vitro using chemotaxis chambers with or without concomitant stimulation with eotaxin or stromal cell-derived factor-1. Cell migration into ischemic myocardium was evaluated by immunohistochemistry. CCR3 and CXCR4 antibodies or local injections of stromal cell-derived factor-1 were used to investigate the role of chemokine expression in the migration capacity of the injected cells. Morphologic analysis included evaluation of apoptosis and capillary density in the ischemic myocardium. RESULTS: Ischemic rat myocardium demonstrated induced messenger RNA expression for the CCR3-binding chemokines eotaxin, RANTES (regulated on activation, normal T expressed and secreted), and monocyte chemotactic protein-3, but not the CXCR4-binding chemokine stromal cell-derived factor-1. Migration of human angioblasts to ischemic rat myocardium was inhibited by a blocking anti-CCR3 monoclonal antibody, but not by a blocking anti-CXCR4 monoclonal antibody, which instead inhibited migration to bone marrow. Finally, intramyocardial injection of stromal cell-derived factor-1 redirected migration of human angioblasts to ischemic rat hearts, resulting in augmented neovascularization, enhanced cardiomyocyte survival, and functional cardiac recovery. CONCLUSIONS: CCR3-dependent chemokine interactions regulate endogenous migration of CD34+ progenitors from bone marrow to ischemic but not to normal myocardium. Manipulating CXCR4-dependent interactions could enhance the efficacy of cell therapy after myocardial infarction.

Connective tissue changes in a mouse model of vein graft disease.

AIM: The extracellular matrix plays an important physiological role in the architecture of the vascular wall. In arterialized vein grafts severe early changes, such as thrombosis and neointimal hyperplasia occur. Paclitaxel is in clinical use as antiproliferative coating of coronary stents. We aimed to investigate the early connective tissue changes in arterialized vein grafts and the influence of perivascular paclitaxel treatment in an in vivo model. METHODS: C57 black mice underwent interposition of the vena cava into the carotid artery. Neointimal hyperplasia, thrombosis, acid mucopolysaccharides (Alcian), collagen fibers (trichrome Masson), elastic fibers, and apoptosis rate (TUNEL) were quantified in paclitaxel treated veins and controls. RESULTS: In both, controls and paclitaxel treated vein grafts acid mucopolysaccharides and elastic fibers were found predominantly in the neointima, whereas collagen fibers were found mainly in the media and adventitia. At 4 weeks postoperatively the neointimal thickness in controls was 52 (13-130) microm, whereas in 0.6 mg/mL l paclitaxel treated veins it was 103 (43-318) microm (P=0.094). At 8 weeks postoperatively paclitaxel treated veins showed a significantly increased neointimal thickness of 136 (87-199) microm compared with 79 (62-146) microm in controls (P=0.032). There was no difference in apoptosis rate between the two groups (P=NS). Even with the lowest concentration of 0.008 mg/mL paclitaxel veins showed a neointimal thickness of 67 (46-205) microm at 4 weeks postoperatively (P=NS vs controls). CONCLUSION: Early vein graft disease is characterised by an accumulation of acid mucopolysaccharides and elastic fibers in the thickened neointima. Paclitaxel treatment increases the neointimal hyperplasia in mouse vein grafts in vivo.

Primary ovarian carcinoid heart disease curatively treated with a two-stage procedure.

Primary ovarian carcinoid disease with cardiac involvement is a very rare syndrome, which requires interdisciplinary management. We report on a patient with primary ovarian carcinoid tumor with severe tricuspid valve insufficiency who was curatively treated after successful tumor resection and tricuspid valve replacement.

Do manual assisting maneuvers increase speed and technical performance in robotically sutured coronary bypass graft anastomoses?

BACKGROUND: Robotic endoscopic coronary artery bypass grafting procedures usually are performed as solo surgery operations. This study aimed to investigate whether manual assistance can reduce suturing times and anastomotic suturing problems in robotic coronary artery surgery. METHODS: In isolated pig hearts, the right coronary artery was excised from the epicardium as a pedicle. This pedicled vessel, which resembles the internal mammary artery, was sutured to the left anterior descending artery using the daVinci telemanipulation system. The anastomosis was performed in a running fashion using 7/0 Pronova. In group 1 (n = 20), the suture was performed by the console surgeon as a solo operation. In group 2 (n = 20), the anastomosis was assisted by a team member using an endo forceps. The operations were performed by five surgeons of different training levels. RESULTS: The overall anastomotic time was 24 +/- 15 min in group 1 and 22 +/- 12 min in group 2. The difference was not significant. The rate for anastomotic suturing problems (thread rupture, knot formation, sling formation, needle bending) was 8 in 20 (40%) in group 1 and 8 in 20 (40%) in group 2 (no difference). Anastomotic times and anastomotic suturing errors were dependent on surgeon experience. All anastomoses in both groups showed correct suture alignment and were probe patent. CONCLUSION: In a wet lab model of robotic coronary anastomoses, assisting maneuvers do not decrease suturing speed. Similar suturing quality can be achieved whether the suture is performed in a solo fashion or in an assisted manner.

Technical challenges in totally endoscopic robotic coronary artery bypass grafting.

OBJECTIVE: Robotic technology is a prerequisite for performance of totally endoscopic coronary artery bypass grafting. During the implementation phase of totally endoscopic coronary artery bypass, surgeon-related technical difficulties might be encountered. It was the aim of this study to assess the incidence of these challenges, to find risk factors, and to describe clinical results associated with technical errors. METHODS: From October 2001 through October 2004, 40 patients received robotically assisted totally endoscopic left internal thoracic artery grafts to the left anterior descending coronary artery system with the da Vinci telemanipulation device. All patients underwent remote access cardiopulmonary bypass perfusion through groin access, and all anastomoses were performed on the arrested heart. RESULTS: Undesirable technical events of various grades occurred in 20 (50%) of 40 patients: bleeding from a port hole in 3 (8%), left internal thoracic artery damage in 3 (8%), epicardial lesion in 3 (8%), remote access perfusion problems in 9 (23%), bleeding from the anastomosis in 4 (10%), and anastomotic stenosis in 2 (5%). There was no hospital mortality. The following differences were noted between patients without technical difficulties (group 1) and those in whom problems occurred (group 2): total operative time of 314 minutes (260-540 minutes) versus 418 minutes (270-690 minutes; P = .007), ventilation time of 6 hours (0-26 hours) versus 14 hours (0-278 hours; P = .004), intensive care unit stay of 20 hours (11-70 hours) versus 44 hours (16-336 hours; P=.183), hospital stay of 7 days (4-13 days) versus 8 days (5-21 days; P = .038), and cumulative freedom from angina at 36 months of 93% versus 100% (P = .317). CONCLUSION: We conclude that technical difficulties during totally endoscopic coronary artery bypass grafting translate into markedly increased operative time, moderately prolonged postoperative ventilation time, and slightly increased hospital stay. Short-term survival and freedom from angina, however, do not seem to be compromised.

Myocardial homing and neovascularization by human bone marrow angioblasts is regulated by IL-8/Gro CXC chemokines.

In the adult, new blood vessel formation can occur either through angiogenesis from pre-existing mature endothelium or vasculogenesis mediated by bone marrow-derived endothelial precursors. We recently isolated endothelial progenitor cells, or angioblasts, in human adult bone marrow which have selective migratory properties for ischemic tissues, including myocardium, to where they home and induce vasculogenesis. Here we show that myocardial production of the IL-8/Gro-alpha CXC chemokine family is significantly increased after acute ischemia, and that this provides a chemoattractant gradient for bone marrow-derived endothelial progenitors, or angioblasts. This chemokine-mediated homing of bone marrow angioblasts to the ischemic heart regulates their ability to induce myocardial neovascularization, protection against cardiomyocyte apoptosis, and functional cardiac recovery. Together, our results indicate that CXC chemokines play a central role in regulating vasculogenesis in the adult, and suggest that manipulation of interactions between chemokines and their receptors on autologous human bone marrow-derived angioblasts could augment neovascularization of ischemic myocardial tissue.

Cell- and gene therapy for ischemic heart disease.

Despite advances in pharmacological therapies, cardiovascular surgery, use of mechanical assist devices, and organ transplantation, more than half of the patients with clinically evident heart failure die within 5 years of the initial diagnosis. The use of cellular cardiomyoplasty and gene therapy offer a promising approach for both the prevention and treatment of heart failure. This review will discuss the current state of these emerging fields and the prospects of introducing the methods into clinical practice. Since functional restoration of the damaged heart presents a formidable challenge, developing strategies for the prevention of post-infarct heart failure remains of utmost priority. New strategies to optimize cell delivery, homing and survival on the one side and safe and efficient application of gene therapy to the failing myocardium on the other side are indispensable in order to achieve myocardial recovery after acute infarction or chronic ischemic damage.

Treatment of double vessel coronary artery disease by totally endoscopic bypass surgery and drug-eluting stent placement in one simultaneous hybrid session.

Hybrid coronary artery revascularization is a combination of minimally invasive coronary artery surgery and catheter-based coronary intervention. Hybrid procedures enable adequate revascularization of patients with multivessel coronary artery disease without complete opening of the chest and with the advantage of the most durable option, a left internal mammary artery (LIMA) graft is placed to the left anterior descending (LAD) artery. The hybrid concept is gaining renewed interest because totally endoscopic LIMA to LAD placement has become feasible and because drug-eluting stents in non-LAD targets may be competitive even for arterial bypass grafts. Simultaneous hybrid procedures would be desirable. We report on a case in which robotic totally endoscopic LIMA to LAD grafting using the da Vinci telemanipulation system was combined with placement of a rapamycin coated stent to the right coronary artery in one single procedure.

Ongoing procedure development in robotically assisted totally endoscopic coronary artery bypass grafting (TECAB).

BACKGROUND: Totally endoscopic coronary artery bypass grafting (TECAB) using robotics requires stepwise introduction into a heart surgery program. It is the aim of this study to evaluate the state of procedure development after continued application of telemanipulation techniques in the clinical setting. We also sought to assess perioperative and intermediate term clinical results after robotically assisted CABG. PATIENTS AND METHODS: From June 2001 to March 2005, robotically assisted CABG using the daVinci system was carried out in 107 patients with single and multi-vessel coronary artery disease. The following procedures were performed: robotically assisted endoscopic left internal mammary artery (LIMA) harvesting and completion of the procedure as conventional CABG, MIDCAB, or OPCAB (n = 22), robotically assisted suturing of LIMA-to-LAD anastomoses during conventional CABG (n = 28), TECAB on the arrested heart using remote access perfusion (n = 48), TECAB on the beating heart using an endostabilizer (n = 8), takedown of adhesions (TECAB intended) (n = 1). RESULTS: Hospital mortality was 0% and cumulative risk adjusted mortality reached 1.6 lives saved versus EuroSCORE predictions. Undesirable surgical events (USE) such as conversion, on table revision, or postoperative revision procedures occurred in 34 out of 107 (32%) patients. Median ventilation time and ICU stay, however, were 11(0-278) hours and 21(11-389) hours, respectively. Cumulative 3 years survival was 100% and freedom from angina at 3 years was 97%. CONCLUSIONS: We conclude that despite being surgically challenging robotically assisted coronary artery surgery can be implemented with acceptable safety. TECAB procedures have reached a reproducible state. Perioperative mortality after robotically assisted CABG may be lower than predicted. Intermediate term clinical results are very satisfactory.

Cell therapy for ischemic heart disease.

Despite advances in pharmacological therapies, cardiovascular surgery, use of mechanical assist devices, and organ transplantation, more than 50% of the patients with clinically evident heart failure die within 5 years of the initial diagnosis. The use of cellular therapy offers a promising approach for both the prevention and treatment of heart failure. This review will discuss the current state of this emerging field and the prospects to introduce the method into clinical practice. Since functional restoration of the damaged heart presents a formidable challenge, developing strategies for the prevention of postinfarct heart failure remains of utmost priority. Recent research has provided evidence that several cell lines including adult or embryonic stem cells, skeletal myoblasts, fetal cardiomyocytes or fibroblasts may be useful in strategies that aim to both prevent and treat heart failure through establishment of new blood vessels supplying surviving heart muscle cells and replacement of damaged heart muscle cells themselves. It is therefore reasonable to anticipate that new strategies will be developed to optimize cell delivery, homing and survival in the failing myocardium improving myocardial recovery after acute or chronic deterioration.

Combined transplantation of skeletal myoblasts and bone marrow stem cells for myocardial repair in rats.

OBJECTIVES: To prove whether intramyocardial transplantation of combined skeletal myoblasts (SM) and mononuclear bone marrow stem cells is superior to the isolated transplantation of these cell types after myocardial infarction in rats. METHODS: In 67 male Fischer rats myocardial infarction was induced by direct ligature of the LAD. Seven days postinfarction baseline echocardiography and intramyocardial cell transplantation were performed. Via lateral thoracotomy 200 microl containing either 10(7) SMs or 10(7) bone marrow-derived mononuclear cells (BM-MNC) or a combination of 5x10(6) of both cell types (MB) were injected in 10-15 sites in and around the infarct zone. In controls (C) 200 microl of cell-free medium were injected in the same manner. Before injection both cell types were stained using a fluorescent cell linker kit (PKH, Sigma). In addition, SMs were transfected with green fluorescent protein. Nine weeks postinfarction follow-up echocardiography was performed and animals were sacrificed for further analysis. RESULTS: At baseline echocardiography there was no difference in left ventricular ejection fraction (LVEF; C, SM, BM-MNC, MB: 60.1+/-3.2, 53.3+/-10.2, 53.1+/-8.7, 49+/-9.0%) and left ventricular end diastolic diameter (LVEDD; C, SM, BM-MNC, MB: 6.5+/-0.8, 5.17+/-0.8, 5.77+/-1.4, 6.25+/-0.8 mm) between the different therapeutic groups. Eight weeks after cell transplantation LVEDD was significantly increased in all animals except those that received a combination of myoblasts and bone marrow stem cells (MB; C, SM, BM-MNC, MB: 7.7+/-0.6 mm, P=0.001; 7.7+/-1.5 mm, P<0.001; 7.7+/-1.1 mm, P=0.005; 6.6+/-1.7 mm, P=0.397. At the same time LVEF decreased significantly in the control group (C), stayed unchanged in animals that received bone marrow stem cells (BM-MNC) and increased in animals that received myoblasts (SM) and a combination of both cell types (MB; C, SM, BM-MNC, MB: 45.3+/-7.0%, P=0.05; 63.9+/-15.4%, P=0.044; 54.3+/-6.3%, P=0.607; 63.0+/-11.5%, P=0.039). CONCLUSIONS: The present data show that the concept of combining SMs with bone marrow-derived stem cells may be of clinical relevance by merging the beneficial effects of each cell line and potentially reducing the required cell quantity. Further studies are required to identify the exact mechanisms underlying this synergy and to allow full exploitation of its therapeutic potential.

Is the axillary artery a suitable cannulation site in aortic surgery?

AIM: The axillary artery is currently gaining interest as an alternative to femoral artery cannulation in aortic surgery. It was the aim of our study to evaluate the feasibility, safety, and efficacy of axillary artery cannulation in a series of patients undergoing surgery of the ascending aorta and/or the aortic arch. METHODS: From 1998 to 2002 cardiopulmonary bypass (CPB) perfusion via the axillary artery was intended in 35 patients (28 male), median age 61 (22-77) years. The underlying disease was acute aortic dissection type A in 22/35 (63%), chronic aortic dissection type A in 2/35 (6%), ascending aortic aneurysm in 8/35 (22%), aortic regurgitation after previous ascending aortic replacement in 1/35 (3%), pseudoaneurysm after Bentall operation in 1/35 (3%) and coronary artery disease with severe arteriosclerosis of the aorta in 1/35 (3%). RESULTS: Conversion to femoral artery or ascending aortic cannulation was necessary in 3 patients. In the other cases, adequate CPB flows of 2.4 l/m2/min were achieved. In 1 case local dissection of the axillary artery occurred after emergency cannulation. No postoperative complications related to axillary artery cannulation, such as upper extremity ischemia, brachial plexus injury, or local wound infection occurred. No new postoperative stroke was noted, hospital mortality was 4/35 (11%) patients. CONCLUSION: Axillary artery cannulation is feasible in the majority of cases and seems to be a safe and effective method in surgery of the ascending aorta and aortic arch. Several disadvantages of femoral artery cannulation and perfusion can be avoided.

Robotic totally endoscopic coronary artery bypass: program development and learning curve issues.

BACKGROUND: The introduction of new procedures in heart surgery is a critical phase that includes learning curves and the risk of increased mortality or morbidity. Totally endoscopic coronary artery bypass grafting using robotic techniques represents such an innovative procedure. The aim of this report is to demonstrate the safe introduction of totally endoscopic coronary artery bypass grafting using a stepwise and modular approach. METHODS: From June 2001 until December 2002, 50 procedures were performed using the da Vinci telemanipulator system. After baseline training the following procedure modules were carried out in a stepwise manner: robotically assisted endoscopic left internal thoracic artery harvesting and completion of the procedure as conventional coronary artery bypass grafting, minimally invasive direct coronary artery bypass, or off-pump coronary artery bypass (n = 19), robotically assisted suturing of left internal thoracic artery to left anterior descending anastomoses during conventional coronary artery bypass grafting (n = 15), totally endoscopic coronary artery bypass grafting on the arrested heart using remote access perfusion and aortic endocclusion coronary bypass grafting (n = 15). One patient was excluded intraoperatively from a robotic procedure due to pleural adhesions. RESULTS: A significant learning curve was observed for left internal thoracic artery takedown time, y(min) = 181 - 39 x ln(x) (x = procedure number) (P <.001), and total operative time in totally endoscopic coronary artery bypass grafting, y(min) = 595 - 87 x ln(x) x = (procedure number) (P =.028). The conversion rate in totally endoscopic coronary artery bypass grafting was 2/15. Intensive care unit stay correlated significantly with total operative time (r =.427, P =.002). There was no hospital mortality. CONCLUSION: Totally endoscopic coronary artery bypass grafting can be safely implemented into a heart surgery program. Learning curves are steep for robotic left internal thoracic artery takedown and for performance of totally endoscopic coronary artery bypass grafting. Long operative times translate into prolonged intensive care unit stay in specific cases but not into increased mortality.